I remember a reference to the phrase "voodoo economics" for Reagan-era tax policy, predicated on the idea of minimising tax to maximise tax revenue.
Clearly if you reduce tax to zero, the government gets no tax income, and if you set tax to 100% nobody has an incentive to do anything. Therefore there's an optimum level for a given economy, but I don't know what it would be for Australia. Given our low population density and geographical position I would say it would have to be higher than most other countries' optimum level.
